MXPA05011045A - Resin composition for use in a froth spraying system. - Google Patents

Abstract

A resin composition for use in a froth spraying system for forming polyurethane foam is disclosed. The resin composition comprises a Mannich polyol, at least one additional polyol other than a Mannich polyol, and a physical blowing agent. The Mannich polyol has a viscosity of at least 4,000 centipoise at 25 .degree.C. The physical blowing agent is selected from the group of volatile non-halogenated C2 to C7 hydrocarbons, hydrofluoro-carbons, hydrochlorocarbons, and mixtures thereof. The physical blowing agent is present in an amount of greater than 10 parts by weight based on 100 parts by weight of the resin composition. A method of forming the polyurethane foam is also provided comprising the steps of providing the resin composition and a polyisocyanate , mixing the resin composition with the polyisocyanate in a mixing chamber to form a mixture, and discharging the mixture from a dispensing gun as the resin composition reacts with the polyisocyanate to form the polyurethane foam.

Description

COMPOSITION OF RESIN FOR USE IN A FOAM SPRAY SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for use in a foam spray system for forming polyurethane foam. 2. Description of Related Art Various hydrofluorocarbons (HFC's) in the industry have been investigated as blowing agents for polyisocyanate-based foams due to their low or non-existent potential for ozone reduction. Such a system would allow the production of an environmentally friendly closed cell polyurethane foam that exhibits an improved cellular structure and that expands in a lower temperature range. These systems of the related arts utilize a resin composition that includes a Mannich polyol, at least one additional polyol other than a Mannich polyol, and chemical blowing agents. Chemical blowing agents increase the cost of preparing the polyurethane foam because the chemical blowing agents react with the polyisocyanate. Therefore, an additional polyisocyanate is required to form the polyurethane foam which increases the cost to produce the polyurethane foam.

Other systems of the related art have been used, in addition to the chemical blowing agent, lower amounts of a physical blowing agent. The physical blowing agent is typically selected from hydrocarbons, hydrofluorocarbons, hydrochlorocarbons, and mixtures thereof. An example is described in US Patent No. 6,534,556 assigned to the assignee of the disclosed invention. The '556 patent uses no more than 10 parts by weight of the physical blowing agent because the resin composition becomes saturated and no additional, physical blowing agent can be added. This is particularly true when the physical blowing agent is R-134a. Additionally, using an amount of 10 parts by weight or less of the physical blowing agent reduces the cost of producing the polyurethane foam. BRIEF DESCRIPTION OF THE INVENTION AND ADVANTAGES The disclosed invention provides a resin composition for use in a foam spray system to form polyurethane foam. The resin composition comprises a Mannich polyol, at least one additional polyol different from a Mannich polyol, and a physical blowing agent. The Mannich polyol has a viscosity of at least 4,000 centipoise at 25 ° C. The physical blowing agent is selected from the group of non-halogenated, volatile C2 to C7 hydrocarbons, hydrofluorocarbons, hydrochlorocarbons, and mixtures thereof. The physical blowing agent is present in an amount greater than 10 parts by weight based on 100 parts by weight of the resin composition. The invention disclosed further provides a method for forming polyurethane foam using the foam spray system. The foam spray system generally includes supply containers, a spray machine, and a dispensing gun that has a mixing chamber. The method provides the resin composition and a polyisocyanate and mixes the resin composition with the polyisocyanate in the mixing chamber to form a mixture. The mixture is discharged from the dispensing gun when the resin composition reacts with the polyisocyanate to form the polyurethane foam. The disclosed invention provides a foam spray system that allows for an improved supply of a resin composition and a polyisocyanate. The foam spray system allows the resin composition to have increased amounts of physical blowing agents that have not previously been advantageously used. The polyurethane foam produced with such a system achieves the desired physical properties and characteristics.

DETAILED DESCRIPTION OF THE INVENTION A foam spray system mixes a resin composition and a polyisocyanate to form a mixture and the mixture is supplied from a dispensing gun to form a polyurethane foam. A first stream carries the resin composition from a storage tank or pressurized container to the dispensing gun. A second current, separated from the first stream, carries the polyisocyanate from a storage tank or a pressurized container to the dispensing gun. The two streams are mixed together in a mixing chamber of the dispensing gun and begin to react. When the continuous mixture reacts, it is supplied from the dispensing gun on or in the direction of a substrate. In one embodiment, the substrate may include a wall having cavities in it to receive the mixture. Other forms of the substrate may include pipes or any other equipment that requires insulation. Typically, upon completion of the reaction, the polyurethane foam acts as an insulation for the substrate. The resin composition includes a physical blowing agent that causes the mixture to foam when the mixture leaves the dispensing gun. However, those skilled in the art recognize that the mixture can not necessarily produce foam when it is supplied from the dispensing gun. Those skilled in the art recognize that the physical blowing agent vaporizes sufficiently and spontaneously when the two combined streams are exposed to atmospheric pressure at discharge. Vaporization of the physical blowing agent produces the foam. It will be understood that the entire physical blowing agent does not need to vaporize instantaneously when it is discharged, although at least a sufficient amount must be vaporized to produce the foam in the discharge from the dispensing gun. The resin composition, in addition to the physical blowing agent, includes a Mannich polyol and at least one additional polyol different from the Mannich polyol. The resin composition may also include a catalyst system, surface agents, flame retardants, fillers, stabilizers, fungicides, pigments or dyes and bacteriostats. The resin composition is substantially free of chemical blowing agents. Chemical blowing agents include any blowing agent that chemically reacts with the resin composition or the polyisocyanate, such as, but not limited to, water, it will be understood that, in the context of the disclosed invention, substantially free of blowing agents The chemical is intended to indicate that the resin composition has less than 5 parts by weight, preferably less than 2.5 parts by weight, and more preferably less than 1.5 parts by weight, based on 100 parts by weight of the resin composition. The Mannich polyol is made by alkoxy treating a Mannich compound, which is the condensation product of phenol or a substituted phenol, formaldehyde, and an alkanoamine, such as diethanolamine. For example, the Mannich reaction is performed by premixing the phenolic compound with a desired amount of the ethanolamine and then slowly adding formaldehyde to the mixture at a temperature below the Novolak formation temperature. At the end of the reaction, the water is extracted from the reaction mixture to provide a crude Mannich reaction product. The Mannich reaction product is then treated with alkoxy with an alkylene oxide such as, for example, propylene oxide, ethylene oxide, or a mixture of propylene oxide and ethylene oxide. The alkylene oxide may suitably comprise from about 80 to 100 parts by weight of propylene oxide and from 0 to about 20 parts by weight of ethylene oxide based on 100 parts by weight of the alkylene oxide. The alkoxy or alkoxylation treatment of the Mannich reaction products is described in US Patents Nos. 3,297,597 and 4,137,265, the descriptions of which are incorporated herein by reference. The treatment with alkoxy or alkoxylation with propylene oxide is carried out by introducing the propylene oxide, preferably under pressure, into a vessel containing the Mannich reaction product. It is not necessary to add a catalyst since the basic nitrogen in this product provides sufficient catalytic activity to stimulate the reaction. Reaction temperatures between about 30 ° C and about 200 ° C can be employed, although the preferred reaction temperatures are in the range of about 90 ° to 120 ° C. Under these conditions, the phenolic hydroxyl group and the alkanolamino hydroxyls are reactive to form hydroxypropyl groups. Unreacted and partially reacted materials are removed from the final condensation product in any suitable manner (eg, by vacuum extraction) to provide light amber to coffee colored liquids having hydroxyl numbers in the range of 400 to 550 and viscosities between approximately 4,000 and 45,000 centipoises at 25 ° C. The Mannich polyol preferably has a viscosity of at least 4,000 centipoise at 25 ° C. In a preferred embodiment of the present invention, the Mannich polyol is present in the resin composition in an amount of 2 to 40 parts by weight based on 100 parts by weight of the resin composition. Preferably, the resin composition has a hydroxyl content of at least 400 mg KOH / g. Additionally, the Mannich polyol preferably comprises an aromatic amine polyol having a hydroxyl content of at least 400 mg KOH / g. The aromatic amine polyol preferably has an amino content of at least 2.8 meq / g. The resin composition also includes at least one additional polyol compound having at least two hydrogens reactive with isocyanate. Compounds having at least two hydrogens reactive with isocyanate preferably have an average hydroxyl number ranging from 150 to 800 mg KOH / g of the compound. Examples of these polyols include polythioether polyols, polyester amides and polyacetals containing hydroxyl groups, aliphatic polycarbonates containing hydroxyl groups, polyoxyalkylene polyethers terminated at amino, polyester polyols, and polyoxyalkylene polyether polyols. In addition, mixtures of at least two of the aforementioned polyols can be used. The term "polyester polyol" as used in this specification and in the claims includes any minor amount of unreacted polyol remaining after the preparation of the non-esterified polyester and / or polyol polyol (eg, glycol), added after the preparation of the polyester polyol. The polyester polyol can include up to about 40 weight percent free glycol. Suitable polyester polyols can be produced, for example, from organic dicarboxylic acids with 2 to 12 carbons, preferably aliphatic dicarboxylic acids with 4 to 6 carbons, and multivalent alcohols, preferably diols, with 2 to 12 carbons, preferably 2 to 6. carbons. Examples of dicarboxylic acids include succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decandicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used individually or in mixtures. Instead of the free dicarboxylic acids, the corresponding dicarboxylic acid derivatives such as the mono- or di-esters of dicarboxylic acid of alcohols with 1 to 4 carbons or dicarboxylic anhydrides can also be used. Mixtures of dicarboxylic acid of succinic acid, glutaric acid and adipic acid are preferred in quantity ratios of 20-35: 35-50: 20-32 parts by weight, especially of adipic acid. Examples of divalent and multivalent alcohols, especially diols, include ethanediol, diethylene glycol, 1,2- and 1,3-propanediol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1, 10-decanediol, glycerin and trimethylolpropanes, tripropylene glycol, tetraethylene glycol, tetrapropylene glycol, tetramethylene glycol, 1,4-cyclohexanedimethanol, or mixtures of at least two of these diols, especially mixtures of 1,4-butanediol, 1,5-pentanediol and 1, 6-hexanediol. In addition, lactone polyester polyols can also be used, for example, e-caprolactone or hydroxycarboxylic acids, for example,? -hydroxycaproic acid. The polyester polyols can be produced by the polycondensation of organic polycarboxylic acids, for example, aromatic or preferably aliphatic polycarboxylic acids and / or derivatives thereof and multivalent alcohols in the absence of catalysts or preferably in an atmosphere of an inert gas, example, nitrogen, carbon dioxide, helium, argon, etc., in the melt at temperatures of 150 ° to 250 °, preferably 180 ° to 220 ° C, optionally under reduced pressure, up to the desired acid value which is preferably less than 10, especially less than 2. In a preferred embodiment, the esterification mixture is subjected to polycondensation at the temperatures mentioned above to an acid value of 30 to 80, preferably 30 to 40, under normal pressure, and then under a pressure less than 500 mbar, preferably 50 to 150 mbar. The reaction can be carried out as a batch process or as a continuous process. When present, excess glycol can be distilled from the reaction mixture during and / or after the reaction, such as in the preparation of polyester polyols containing low free glycol usable in the present invention. Examples of suitable esterification catalysts include iron, cadmium, cobalt, lead, zinc, antimony, magnesium, titanium and tin catalysts in the form of metals, metal oxides or metal salts. However, polycondensation can also be carried out in the liquid phase in the presence of diluents and / or chlorobenzene for the aziotropic distillation of the condensation water. To produce the polyester polyols, the organic polycarboxylic acids and / or derivatives thereof and multivalent alcohols are preferably polycondensed in a mol ratio of 1: 1-1: 8, more preferably 1: 1.05-1.2. After trans-esterification or esterification, the reaction product can be reacted with an alkylene oxide to form a polyester polyol mixture. This reaction is desirably catalyzed. The temperature of this process should be from about 80 ° C to 170 ° C, and the pressure should generally vary from about 1 to 40 atmospheres. Although aromatic polyester polyols can be prepared from substantially pure reactant materials, more complex ingredients can be used, such as side stream, waste debris or fragments of the manufacture of phthalic acid, terephthalic acid, dimethyl terephthalate, polyethylene terephthalate. , and similar. Compositions containing phthalic acid residues for use in the invention are (a) by-products containing ester of the manufacture of dimethyl terephthalate, (b) fragments of polyalkylene terephthalates, (c) phthalic anhydride, (d) residues of the manufacture of phthalic acid or phthalic anhydride, (e) terephthalic acid, (f) residues from the manufacture of terephthalic acid, (g) isophthalic acid, (h) trimellitic anhydride, and (i) combinations thereof. These compositions can be converted by reaction with the polyols of the invention to polyester polyols through conventional transesterification or esterification processes. Other materials that contain phthalic acid residues are polyalkylene terephthalates, especially polyethylene terephthalate (PET), waste or fragments. Still other residues are residues of the dimethyl terephthalate (DMT) process, which are waste residues or fragments of the manufacture of DMT. The term "residue of the DMT process" refers to the purged residue which is obtained during the manufacture of DMT in which the p-xylene is converted through oxidation and esterification with methanol to the desired product in a reaction mixture together with a complex mixture of by-products. The desired DMT and the volatile methyl p-toluate byproduct are removed from the reaction mixture by distillation leaving a residue. The DMT and the methyl p-toluate are separated, the DMT is recovered and the methyl p-toluate is recycled for oxidation. The remaining residue can be purged directly from the process or a portion of the waste can be recycled for oxidation and the remainder is separated from the process or, if desired, the waste can be further processed as, for example, by distillation, heat treatment and / or methanolysis to recover useful constituents that might otherwise be lost, before purging the waste from the system. The residue that is finally purged from the process, with or without additional processing, is called the residue of the DMT process. Polyoxyalkylene polyether polyols are preferred, which can be obtained by known methods for use as the additional polyhydroxyl compounds. For example, polyether polyols can be produced by anionic polymerization with alkali hydroxides such as sodium hydroxide or potassium hydroxide or alkali alcoholates, such as sodium methylate, sodium ethylate, or potassium ethylate or potassium isopropylate as catalysts and with the addition of at least one initiator molecule containing 2 to 8, preferably 3 to 8, reactive hydrogens or by cationic polymerization with Lewis acids such as antimony pentachloride, boron trifluoro-etherate, or bleaching clay as catalysts of one or more alkylene oxides with 2 to 4 carbons in the alkylene radical. Any suitable alkylene oxide such as 1,3-propylene oxide, 1,2- and 2,3-butylene oxide, amylene oxide, styrene oxide, and preferably ethylene oxide and 1,2-oxide may be used. -propylene and mixtures of these oxides. The polyalkylene polyether polyols can be prepared from other starting materials such as tetrahydrofuran and mixtures of alkylene oxide-tetrahydrofuran; epi alohydrins such as epichlorohydrin; as well as aralkylene oxides such as styrene oxide. The polyalkylene polyether polyols can have hydroxyl groups either primary or secondary.

Polyoxyethylene glycol, polyoxypropylene glycol, polyoxybutylene glycol, polytetramethylene glycol, block copolymers, for example, combinations of polyoxypropylene and polyoxyethylene glycols, poly-1,2-oxybutylene and polyoxyethylene glycols, poly-1,4-tetramethylene glycol and polyethylene glycol are included among the polyether polyols. poly-oxyethylene glycols, and copolymer glycols prepared from mixtures or the sequential addition of two or more alkylene oxides. The polyalkylene polyether polyols can be prepared by any known process such as, for example, the process described by Wurtz in 1859 and the Encyclopedia of Chemical Technology, Vol. 257-262, published by Interscience Publishers, Inc. (1951) or in U.S. Patent No. 1,922,459. Preferred polyethers include the alkylene oxide addition products of polyhydric alcohols such as ethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol. , hydroquinone, resourcinol glycerol, glycerin, 1,1-trimethylolpropane, 1,1,1-trimethylolethane, pentaerythritol, 1,2,6-hexantriol, a-methyl glucoside, sucrose and sorbitol. Also included within the term "polyhydric alcohol" are phenol-derived compounds such as 2,2-bis (4-hydroxyphenyl) -propane, commonly known as Bisphenol A.

A further preferred polyether polyol of the present invention is Voranol "370, a sucrose-based polyether polyol having a hydroxyl number of about 370 and commercially produced by the Dow Chemical Company." Further preferred polyether polyols are Pluracol polyether tetroles PEP 450 and 550 having hydroxyl numbers of about 560 and 450, respectively and commercially produced by BASF Corporation, and Pluracol GP 730 which is a polyether triol having a hydroxyl number of about 270 and available commercially available from BASF Corporation Suitable initiators of organic amine which can be condensed with alkylene oxides include aromatic amines such as aniline, N-alkylphenylenediamines, 2,4'-, 2,2'-, and 4,4'-methylenedianiline, 2,6- or 2,4-toluenediamine, toluenediamine vicinal, o-chloroaniline, paminoaniline, 1,5-diaminonaphthalene, methylene dianiline, the various products of co ndensation of aniline and formaldehyde, and isomeric diaminotoluenes; and aliphatic amines such as mono-, di-, and trialkanolanes, ethylenediamine, propylene diamine, diethylene triamine, methylamine, ethanolamine, diethanolamine, N-methyl- and N-ethylethanolamine, N-methyl- and N-ethyldiethanolamine, triethanolamine, triisopropanolamine, , 3-diaminopropane, 1,3-diaminobutane, and 1,4-diaminobutane. Preferred amines include polyoxypropylene diamine, such as Jeffamine "D-230 commercially produced by Huntsman Corporation.It will be understood that polyols initiated by an amine may also be initiated with a polyhydric alcohol, such as when a mixed initiator of an aliphatic amine is used. / polyhydric alcohol as an amine / sucrose packet Suitable polyhydric polythioethers which can be condensed with alkylene oxides include the condensation product of thiodiglycol or the reaction product of a dicarboxylic acid as described above for the preparation of the polyesters containing hydroxyl with any other suitable thioether glycol The hydroxyl-containing polyester can also be a polyester amide as obtained by including some polyester amide as obtained by including some amine or amino alcohol in the reactants for the preparation of polyesters. Further, polyester amides can be obtained by condensing an amino alcohol such as ethanolamine with the polycarboxylic acids stated above or the same can be made using the same components that make up the hydroxyl-containing polyester with only a portion of the components that are a diamine. such as ethylenediamine. Suitable polyacetals which can be condensed with alkylene oxides include the reaction product of formaldehyde or other suitable aldehyde with dihydric alcohol or an alkylene oxide such as those described above. Suitable aliphatic thiols which can be condensed with alkylene oxides include alkanols containing at least two -SH groups such as 1, 2-ethanedithiol, 1,2-propanedithiol, 1,2-propandithiol, and 1,6-hexandithiol; alkenothiols such as 2-buten-l, 4-dithiol; and alkynothiols such as 3-hexin-l, 6-dithiol. In a preferred embodiment of the disclosed invention, at least one additional polyol is selected from the group of polyether polyols initiated with sucrose, polyether tetroles, polyether thiols, and mixtures thereof. At least one additional polyol is present in an amount greater than 0 to 35 parts by weight based on 100 parts by weight of the resin composition. As described above, physical blowing agents are those that boil when the mixture reacts exothermically and forms the polyurethane foam, preferably at 50 ° C, or less. The most preferred physical blowing agents are those that have a ozone depletion potential of zero. Examples of physical blowing agents are non-halogenated, volatile hydrocarbons, having two to seven carbon atoms such as alkanes, alkenes, cycloalkanes having up to 6 carbon atoms, dialkyl ether, cycloalkylene ethers and ketones; and hydrofluorocarbons (HFCs). Examples of non-halogenated, volatile hydrocarbons include linear or branched alkanes, for example, butane, isobutane, 2,3-dimethylbutane, n- and isopentane and mixtures of pentane of technical grade, n- and isohexanes, n- and isoheptans , n- and isooctans, n- and isononanes, n- and isodecanes, n- and isoundecanes, and n- and isodedecanes. Since very good results are obtained with respect to the stability of the emulsions, the processing properties of the reaction mixture and the mechanical properties of the polyurethane foam products produced when n-pentane, isopentane or n-hexane is used, or a mixture thereof, these alkanes are preferably used. In addition, specific examples of alkenes are 1-pentene, 2-methylbutene, 3-methylbutene, and 1-hexene; of cycloalkanes are cyclobutane, preferably cyclopentane, cyclohexane or mixtures thereof; specific examples of linear or cyclic ethers are dimethyl ether, diethyl ether, methyl ethyl ether, vinyl methyl ether, vinyl ethyl ether, divinyl ether, tetrahydrofuran and furan; and specific examples of ketones are acetone, methyl ethyl ketone and cyclopentanone.

Preferably, cyclopentane, n- and isopentane, n-hexane, and mixtures thereof are employed. Suitable hydrofluorocarbons include difluoromethane (HFC-32); 1,1,1,1-tetrafluoroethane (HFC-134a); 1,1,2,2-tetrafluoroethane (HFC-134); 1,1-difluoroethane (HFC-152a); 1,2-difluoroethane (HFC-142), trifluoromethane; heptafluoropropane (R-227a); hexafluoropropane (R-136); 1,1,1-trifluoroethane; 1, 1, 2-trifluoroethane; fluoroethane (R-161); 1, 1, 1, 2, 2-pentafluoropropane; pentafluoropropylene (R-2125a) -; 1, 1,1,3- (tetrafluoropropane; tetrafluoropropylene (R-2134a); difluoropropylene (R-2152b); 1, 1, 2, 3, 3-pentafluoropropane; 1, 1, 1,3, 3-pentafluoro-n-butane; and 1, 1, 1, 3, 3 -pentafluoropentane (245fa). In a preferred embodiment, the physical blowing agent is selected from the group of cyclopentane, isopentane, n-pentane, trans-1,2-dichloroethylene, and mixtures thereof. Physical blowing or insufflation is present in an amount greater than 10 parts by weight, preferably greater than 10 to 40 parts by weight, and more preferably greater than 10 to 30 parts by weight, based on 100 parts by weight of the resin composition . In a more preferred embodiment, the physical blowing agent is cyclopentane. The cyclopentane has a boiling point of 322 K (49 ° C to 760 mm / Hg) and easily vaporizes to produce froth in the mixture when it leaves the dispensing gun. The mixture may not produce foam when it leaves the dispensing gun depending on the processing temperatures of the mixture. The cyclopentane can be added to the resin composition in the dispensing gun as a separate stream; mixing in the supply container of the resin composition immediately before being supplied; or it can be pre-mixed in the resin composition, stored and shipped in the pressurized container to a manufacturer of the polyurethane foams of the present invention. To make the resin composition by any of these methods, the cyclopentane is measured in the resin composition and, optionally, although it is preferably mixed until a homogeneous solution is formed. In one embodiment the container containing the resin composition is pressurized at 10,545 to 21.09 kg / cm2 (150-300 psig), and depending on the type of delivery method employed as further described below, it can also be pre-combined with a inert gas such as nitrogen. The amount of cyclopentane employed will depend on the desired density of the polyurethane foam and the limits of its solubility in a particular resin composition. However, the compositions of the related art were limited by the physical blowing agent because the resin composition is saturated in a relatively small amount. For example, when the physical blowing agent is R-134a, the resin composition is saturated at about 10 parts by weight based on 100 parts by weight of the resin composition. Therefore, in order to ensure that the polyurethane foam has the desired density, physical blowing agents or additional chemical blowing agents have to be used. The disclosed invention utilizes the physical blowing agent in an amount greater than 10 parts by weight based on 100 parts by weight of the resin composition, which eliminates the need for physical blowing agents or additional chemical blowing agents. This is particularly advantageous since the chemical blowing agents react with the polyisocyanate and generally require more polyisocyanate to form the polyurethane foam. Since the disclosed invention is substantially free of chemical blowing agents, less polyisocyanate is consumed and the cost of producing the polyurethane foam is also reduced. The resin composition may also include a catalyst system. The catalyst system is selected from at least one of a curing catalyst, a blowing catalyst, and a freezing catalyst. The catalyst system can be used to greatly accelerate the reaction of the isocyanate-reactive hydroxyl group-containing compounds with the modified or non-modified polyisocyanates. The curing catalysts also function to shorten the adhesive time, to promote resistance to curing and to prevent shrinkage of the foam. Suitable curing catalysts are organometallic catalysts, preferably organo-lead catalysts, although it is possible to employ metals such as tin, titanium, copper, mercury, cobalt, nickel, iron, vanadium, antimony, bismuth, lithium, and manganese. Preferred curing catalysts include lead octoate and lead naphthanate. The curing catalyst is preferably present in an amount from 0.01 to 0.9 parts by weight based on 100 parts by weight of the resin composition. Blowing catalysts include tertiary amines and promote the formation of urethane bonds. Examples of blowing catalysts are polyoxypropylenediamines which include triethylamine, 3-methoxypropyl dimethylamine, triethylene diamine, tributylamine, dimethylcyclohexylamine, dimethylbenzylamine, N-methyl-, N-ethyl- and N-cyclohexylmorpholine, N, N, N ', N' -tetramethylethylenediamine. , N, N, N ', N' -tetramethylbutanediamine or -hexandiamine, N, N, N'-trimethylisopropylpropylenediamine, pentamethyldiethylenetriamine, tetramethyldiaminoethyl ether, bis (-dimethylaminopropyl) urea, dimethylpiperazine, l-methyl-4-dimethylaminoethylpiperazine, 1,2- dimethyl imidazole, 1-azabicyclo [3.3.0] octane and preferably 1,4-diazabicyclo [2.2.2] octane, and alkanolamine compounds, such as triethanolamine, triisopropanolamine, N-methyl- and N-ethyldiethanolamine and dimethylethanolamine. Another type of blowing catalysts are the tertiary amine ether catalysts. Typical tertiary amine ether blowing catalysts include, but are not limited to, N, N, N, N "-tetramethyl-2, 2'-diaminodietyl ether, 2-dimethylaminoethyl-1,3-dimethylaminone-propyl ether.; and N, N-dimorpholinoethyl ether. Pentamethyl diethylenetriamine is more preferred. The blowing catalyst is preferably present in an amount from 0.01 to 3 parts by weight based on 100 parts by weight of the resin composition. The blowing catalyst can be used in its pure form, or dissolved in a carrier such as a glycol. When the catalyst system is dissolved in a carrier, the amounts set forth herein as parts by weight refer to the amount of the catalyst system and do not include the weight of the carrier.

Preferably, the catalyst system of the present invention includes at least one curing catalyst and at least one blowing catalyst described above. More preferably, the catalyst system also includes the freezing catalyst, such as triethylenediamine in a dipropylene glycol carrier, which is commercially produced under the trade name Dabco "LV-33 by Air Products Corporation." The freezing catalyst is preferably present in a amount from 0.01 to 3 parts by weight based on 100 parts by weight of the resin composition.The resin composition can also include a flame retardant.The flame retardant is preferably present in an amount from 5 to 25 parts by weight based in 100 parts by weight of the resin composition Examples of suitable flame retardants are tricresyl phosphate, tris (2-chloroethyl) phosphate, tris (2-chloropropyl) phosphate, and tris (2,3-dibromopropyl) phosphate. Still another suitable flame retardant is PHT 4 Diol, Tetrabromophthalic Acid, commercially available from Great Lakes Chemical Company. halogen-substituted atoms, it is also possible to use inorganic or organic flame retardants, such as phosphorous red, aluminum oxide hydrate, antimony trioxide, arsenic oxide, ammonium polyphosphate (Exolit) and calcium sulfate, molybdenum trioxide, ammonium molybdate, ammonium phosphate, pentabromodiphenyloxide, 2,3-dibromopropanol, hexabromocyclododecane, dibromoethyldibromocyclohexane, expandable graphite or derivatives of cyanuric acid, for example, melamine, or mixtures of two or more flame retardants, for example, ammonium polyphosphates and melamine, and, if desired, corn starch, or ammonium polyphosphate, melamine, and expandable graphite and / or, if desired, aromatic polyesters, for the purpose of retarding the flame in the polyisocyanate polyaddition products. A surface agent may also be included in the resin composition and the surface agent preferably is present in an amount from 0.01 to 5.0 parts by weight based on 100 parts by weight of the resin composition. Examples of suitable surface agents that can be used are compounds which serve to support homogenization of the starting materials and can also regulate the cellular structure of the polyurethane foam. Specific examples are salts of sulfonic acids, for example, alkali metal salts or ammonium salts of fatty acids such as oleic or stearic acid, of dodecylbenzene or dinaphthylmethanedisulfonic acid, and ricinoleic acid; foam stabilizers, such as siloxanoxyalkylene copolymers and other organopolysiloxanes, oxyethylated alkyl phenols, oxyethylated fatty alcohols, paraffinic oils, castor oil esters, ricinoleic acid esters. Turkey red oil and peanut oil, and cellular regulators, such as paraffins, fatty alcohols, and dimethylpolysiloxanes. A non-silicone surface agent, particularly preferred, is LK-443 commercially produced by Air Products Corporation. The polyisocyanate which can be used in the present invention includes all essentially aliphatic, cycloaliphatic, araliphatic and preferably aromatic multivalent isocyanates. Specific examples include: alkylene diisocyanates with 4 to 12 carbons in the alkylene radical such as 1,1-didocyanate -dodecane, 2-ethyl-1, 4-tetramethylene diisocyanate, 2-methyl-1, 5-diisocyanate pentamethylene, 1,4-tetramethylene diisocyanate and preferably 1,6-hexamethylene diisocyanate, cycloaliphatic diisocyanates such as 1,3- and 1,4-cyclohexane diisocyanate as well as any mixture of these isomers, l-isocyanate-3,3 , 5-trimethyl-5-isocyanatomethyl-cyclohexane (isophorone diisocyanate), 2,4- and 2,6-hexahydrotoluene diisocyanate as well as the corresponding isomeric diisocyanate mixtures of, 4'-, 2,2'- and 2,4'-dicyclohexylmethane as well as the corresponding isomeric mixtures and preferably aromatic diisocyanates and polyisocyanates such as 2,4- and 2,6-toluene diisocyanate and the corresponding isomeric diisocyanate mixtures of 4,4'-, 2,4'- and 2,2'-diphenylmethane and the corresponding isomeric mixtures, mixtures of 4,4'- and 2,4'-diphenylmethane diisocyanates and polyphenylenepolymethylene polyisocyanates (polymeric MDI), as well as as mixtures of polymeric MDI and toluene diisocyanates. Frequently, the polyisocyanate can include the so-called modified multivalent isocyanates, that is, products obtained by the partial chemical reaction of diisocyanates and / or organic polyisocyanates are used. Examples include diisocyanates and / or polyisocyanates containing ester groups, urea groups, biuret groups, allophanate groups, carbodiimide groups, isocyanurate groups, and / or urethane groups. Specific examples include preferably aromatic polyisocyanates containing urethane groups and having an NCO content of 15 to 33.6 parts by weight, preferably 21 to 32 parts by weight, based on 100 parts by weight, for example with diols, triols, dialkylene glycols, low molecular weight trialkylene glycols, or polyoxyalkylene glycols with a molecular weight of up to 1500; 4,4' modified diphenylmethane or 2,4- and 2, 6-toluene, where examples of di- and polyoxyalkylene glycols that may be used individually or as mixtures include diethylene glycol, dipropylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, and polyoxypropylene polyoxyethylene glycols or -triols. The prepolymers containing NCO groups with an NCO content of 9 to 25 parts by weight, preferably 14 to 21 parts by weight, based on 100 parts by weight and produced from the polyester polyols and / or preferably polyether polyols described later; Also suitable are the 4,4' diphenylmethane, mixtures of 2,4'- and 4,4'-diisocyanate 'diphenylmethane, 2,4- and / or 2,6-toluene or polymeric MDI. In addition, liquid polyisocyanates containing carbodiimide groups having an NCO content of 15 to 33.6 parts by weight, preferably 21 to 32 parts by weight, based on 100 parts by weight, have also proven to be suitable, for example, based on diisocyanate of 4,4'- and 2,4'- and / or 2, 2'-diphenylmethane and / or 2,4'- and / or 2,6-toluene diisocyanate. Optionally modified polyisocyanates may be mixed together or mixed with unmodified organic polyisocyanates such as 2,4'- and 4,4'-diphenylmethane, polymeric MDI, 2,4'- and / or 2, 6-toluene.

The organic polyisocyanates that may be employed include aromatic, aliphatic, and cycloaliphatic polyisocyanates and combinations thereof. Representative of these types are diisocyanates such as m-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, mixtures of 2,4- and 2,6-toluene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, cyclohexane-1,4-diisocyanate, diisocyanate (and isomers) of hexahydrotoluene, naphthalene-1,5-diisocyanates, 1-methoxyphenyl-2,4-diisocyanate, 4,4'-diphenylmethane diisocyanate, diisocyanate mixtures of 4,4'- and 2,4'-diphenylmethane, 4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3'-dimethyl-4-diisocyanate, 4'-biphenyl and 3,3'-dimethyldiphenylmetant-4,4'-diisocyanate; triisocyanates such as 4,4 ', 4"-triphenylmethane triisocyanate, and 2, 4,6-toluene triisocyanate; and tetraisocyanates such as 4,4'-dimethyldiphenylmethane-2,2', 2, 5'-tetraisocyanate and polymeric polyisocyanates such as polymethylene polyphenylene polyisocyanate, and mixtures thereof.The 4,4'-diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, or mixtures thereof for rigid foams are especially useful due to their availability and properties. or a mixture of the above with toluene diisocyanates for semi-rigid foams, or raw polyisocyanates can be used in the compositions of the present invention, such as crude toluene diisocyanate obtained by the phosgenation of a mixture of toluene diamines or diphenylmethane isocyanate. crude obtained by phosgenation of crude isocyanates as described in US Patent No. 3,215,652. In a preferred embodiment, the system of The foam composition includes a resin supply container, a polyisocyanate supply container, a spray machine, and a dispensing gun having a mixing chamber. Each of the supply containers can be pressurized as understood by those skilled in the art. The resin composition is provided in a stream from the resin supply vessel to the spraying machine and from the spraying machine to the dispensing gun. The resin composition is provided separately from the isocyanate, such that the isocyanate is also provided in a stream from the polyisocyanate supply vessel to the spray machine and from the spray machine to the dispensing gun. The spray system according to the present invention monitors flammable gas levels to detect leaks in the stream of the resin composition. In order to monitor these gas levels, the supply container for the resin composition is located in a storage room, which also contains the spraying machine and the hoses, and is isolated from an area to be sprayed. This area could be classified as Class 1, Zone 2, Group D. The storage room typically also includes the spraying machine. The spray machine is preferably a fixed dosing machine with two positive displacement pumps, one for the isocyanate and the other for the resin. The spray machine heats the two liquid components to the desired temperature (typically between 26-66 ° C), pressurizes the components (typically between 4000-20,400 kPa), then supplies them through separate hoses to the dispensing gun with the Mixing head A spray operator sprays the foam on the desired substrate, such as a concrete wall, OSB, etc. Typical manufacturers of spray machines are Gusmer Inc, Graco Inc, and Glas-Craft. The storage room is also isolated from an operation chamber. The operation chamber stores electrical components that operate the sprinkler system, such as a generator, a compressor, and / or an electrical panel. It is important that the operating chamber is sealed from the storage room in the event of a leak in the flammable gas system because any spark generated in the electrical components can ignite an explosion. In operation, a truck could have each of these areas located in a truck box. Since these areas are separate, the complete box of the truck does not need to be explosion proof, only the area that stores the supply vessels needs to be explosion proof. The cost to produce the polyurethane foam is significantly reduced if only a portion of the truck platform needs to be explosion proof because this reduces the cost of the equipment required to spray the materials. The disclosed invention monitors flammable gas levels by placing sensors in the storage room near the spraying machine and the supply containers. When flammable gas levels are detected above a predetermined threshold, then the foam spray system is deactivated. Preferably, the foam spray system is deactivated when the flammable gas level reaches 20%. Additionally, an alarm can be activated to alert the user of flammable gas levels when it reaches 10%. Additionally, a sensor in the user monitors flammable gas levels in the area where the polyurethane foam is being sprayed to alert the user of flammable gas levels in the spray area. If flammable gas levels are detected in the storage room, after deactivating the foam spray system, the storage room is dewatered to reduce flammable gas levels in the storage room. At least one fan is placed inside the storage room to extract the flammable gas. The foam spray system is re-activated in response to flammable gas levels that fall below the predetermined threshold. Also, if the flammable gas levels in the area to be sprayed are above the predetermined threshold, the operator is notified. The area to be sprayed, if appropriately dewatered, may include attached areas such as, but not limited to, low-rise basements and the like. The foam spray system also includes at least one reactant supply tank to force the gas pressure to drive the reactants from the supply vessels and a fixed ratio positive displacement pump, designed specifically for the spray application of polyurethane foams. Any means can be used to force the pressure to drive the reactants from the supply vessels. Typically, an inert, gaseous, pressurized propellant, such as a nitrogen tank, is used that has outputs through valves that communicate through suitable conduits with the inlets to the supply vessels. The supply vessels are kept under pressure to provide the driving force necessary to drive the reactants from the supply vessels. The pressure in pressurized supply vessels is generally 10,545 to 21.09 kg / cm2 (150-300 psig). However, the pressure can be as low as 50 psig without using an additional pump. If an additional pump is used to extract the component from the container, then the pressure can be as low as 0.03515 kg / cm2 (0.5 psig) to act as a positive pressure and to prevent a vacuum from occurring in the container. It is generally necessary, for the proper functioning of the foam spray system, that the viscosity of the contents of each of the supply vessels, is not greater than about 1200 cps at 25 ° C. And more preferably not greater than about 800 cps. Of course, this means that the materials in each tank may have to be selected or formulated appropriately, may be as the case may be, in order to meet this viscosity requirement. The viscosity values mentioned herein are measured at 25 ° C and at 5,624 kg / cm2 (80 psig (544 psi)). When using the fixed ratio, the positive displacement pump, designed specifically for the spray application of polyurethane foams, the volume ratio of the isocyanate stream and the current of the resin composition, can be maintained at 1: 1 . EXAMPLES The following examples are intended to illustrate, but in no way limit, the scope of the present invention. The foam spray system used in this example comprises: (a) a first supply container for supplying the isocyanate reactant, (b) a second supply container for supplying the resin composition, (c) a pressure tank of nitrogen having a valve outlet in communication, through a distribution valve, with inlets to the two supply vessels, and (d) a fixed displacement positive displacement pump, (e) and an LEL detector (limit of lower explosion) commercially available from BW Technologies and Dr ger. The components that make up the resin composition are listed in Table 1, below, and are in parts by weight, unless otherwise indicated.

Table 1: Resin Composition The Mannich polyol is Mannich based and has a functionality of about 4 and a hydroxyl number of about 470. The Mannich polyol is commercially available as Thanol® R470X from Dow Chemical. The additional polyol is an ethylene diamine based on a polyether polyol having a hydroxyl number of about 800 and a functionality of about 4. The additional polyol is commercially available from Jeffol® R290 from Huntsman Petrochemical. The surface agent is an organic surface agent, which is not silicone, commercially available as LK-221® from Air Products and Chemicals. Catalyst A is a low viscosity liquid amine catalyst which is a mixture of 20% triethylene diamine and 80% dimethylethanolamine. Catalyst A is an amine based catalyst commercially available as DABCO 'R-8020 from Air Products and Chemicals. Catalyst B is lead octoate having approximately 24% lead. Catalyst C is an amine-based catalyst commercially available from Toyocat as RX-5. The physical blowing agent is cyclopentane having a boiling point of about 49 ° C, commercially available as EXXOL ™ HP-95 from Exxon Mobil Chemical. The chemical blowing agent is water. The flame retardant is tris- (chlorosopropyl) phosphate. The crosslinking agent A is glycerin having a functionality of three. The FR agent acts as a flame retardant and is an aromatic polyester polyol having a functionality of about 2 and a hydroxyl number of about 305 mg KOH / g, commercially available from Invista as TerateT 4020. The resin composition of the Table 1 is sprayed in a volumetric ratio, 1: 1 with a polyisocyanate through the foam spray system described above. The polyisocyanate is polyphenylenepolymethylene polyisocyanates (Polymeric MDI) commercially available as Lupranate M20S from BASF Corp. The resin composition and the polyisocyanate were reacted to form the polyurethane foam.

Table 2 below lists the physical properties for a sample of the resulting polyurethane foam having the dimensions 2.54 x 10.16 x 10.16 cm (1"x 4" x 4") .The sample was tested in accordance with ASTM D 1622- 98"Standard Test Method for Apparent Density of Rigid Cellular Plastics", ASTM D 1621-00"Standard Test Method for Comprehensive Properties of Rigid Cell Plastics" Procedure A, ASTM C 518-98"Standard Test Method for Stable State Thermal Transmission Properties through the Heat Flow Meter Apparatus ", ASTM D 2126-99" Standard Test Method for the Response of Rigid Cell Plastics to the Process of Thermal and Moisture Aging ", ASTM E 96- 00"Standard Test Method for Transmission & Water Vapor Materials ", Procedure A, ASTM D 6226-98" Standard Test Method for Open Cell Content of Rigid Cell Plastics "and ASTM D 2842-97" Standard Test Method for Water Absorption of Plastics Rigid Cells ".

Table 2: Physical Properties of Polyurethane Foam The polyurethane foam sample was also subjected to dimensional stability analysis. Table 3 illustrates the results of the dimensional stability analysis, listed in% change in volume.

Table 3: Dimensional Stability Analysis The polyurethane foams formed in accordance with the disclosed invention have satisfactory dimensional stability. After 24 hours at 80 ° C, Example 1 had a 0.55% change in volume and Example 2 had a 1.10% change in volume, both were measured from the volume of the original sample. After 7 days at 80 ° C, Example 1 had 3.12% change in volume and Example 2 had 2.32% change in volume, were measured from the volume of the original sample. Obviously, many modifications and variations of the present invention are possible in perspective of the above teachings. The invention may be practiced in a manner different from that specifically described within the scope of the appended claims.

Claims (32)

1. CLAIMS 1.- A resin composition for use in a foam spray system for forming polyurethane foam, said resin composition is characterized in that it comprises: a Mannich polyol having a viscosity of at least 4,000 centipoise at 25 ° C; at least one additional polyol other than a Mannich polyol; and a physical blowing agent selected from the group of hydrocarbons C2 to C7 non-halogenated, volatile, hydrofluorocarbons, hydrochlorocarbons, and mixtures thereof, and present in an amount greater than 10 parts by weight based on 100 parts by weight of the composition of resin.
2. 2. - A resin composition according to claim 1, characterized in that said resin composition is substantially free of chemical blowing agents.
3. 3. - A resin composition according to claim 2, characterized in that said physical blowing agent is selected from the group of cyclopentane, iopentane, n-pentane, trans-l, 2-dichloroethylene, and mixtures thereof.
4. 4. - A resin composition according to claim 1, characterized in that said physical blowing agent is present in an amount greater than 10 to 40 parts by weight based on 100 parts by weight of said resin composition.
5. 5. - A resin composition according to claim 1, characterized in that said resin composition has a hydroxyl content of at least 400 mg KOH / g.
6. 6. A resin composition according to claim 1, characterized in that it further comprises a flame retardant present in an amount from 5 to 25 parts by weight based on 100 parts by weight of said resin composition.
7. 7. - A resin composition according to claim 1, characterized in that said Mannich polyol comprises an aromatic amino polyol having a hydroxyl content of at least 400 mg KOH / g.
8. 8. - A resin composition according to claim 7, characterized in that said Mannich polyol comprises an aromatic amino polyol having an amino content of at least 2.8 meq / g.
9. 9. - A resin composition according to claim 7, characterized in that said Mannich polyol is present in an amount of from 20 to 40 parts by weight based on 100 parts by weight of said resin composition.
10. 10. A resin composition according to claim 1, characterized in that said at least one additional polyol is selected from the group of polyether polyols initiated with sucrose, polyether tetroles, polyether triols, and mixtures thereof.
11. 11. - A resin composition according to claim 1, characterized in that said at least one additional polyol is present in an amount greater than 0 to 35 parts by weight based on 100 parts by weight of said resin composition.
12. 12. - A resin composition according to claim 1, characterized in that it further comprises a catalyst system comprising at least one of a curing catalyst, a blowing catalyst, and a freezing catalyst.
13. 13. - A resin composition according to claim 12, characterized in that said curing catalyst comprises lead octoate present in an amount from 0.01 to 0.9 parts by weight based on 100 parts by weight of said resin composition.
14. 14. - A resin composition according to claim 12, characterized in that said blowing catalyst comprises one of pentamethyl diethylenetriamine and polyoxypropylene diamine and the blowing catalyst is present in an amount from 0.01 to 3 parts by weight based on 100 parts by weight of said resin composition.
15. 15. - A resin composition according to claim 12, characterized in that said freezing catalyst comprises triethylenediamine in a dipropylene glycol carrier and the freezing catalyst is present in an amount from 0.01 to 3 parts by weight based on 100 parts by weight of said resin composition.
16. 16. A resin composition according to claim 1, characterized in that it further comprises a surface agent present in an amount from 0.01 to 5.0 parts by weight based on 100 parts by weight of said resin composition.
17. 17. A method for the formation of a polyurethane foam that uses a foam spray system that includes supply containers, a spray machine, and a dispensing gun that has a mixing chamber, said method is characterized in that it comprises the steps of: providing a resin composition comprising a Mannich polyol having a viscosity of at least 4,000 centipoise at 25 ° C, at least one additional polyol other than a Mannich polyol, and a physical blowing agent selected from the group of C2 to C7 hydrocarbons non-halogenated, volatile, hydrofluorocarbons, hydrochlorocarbons, and mixtures thereof, and used in an amount greater than 10 parts by weight based on 100 parts by weight of the resin composition; provide a polyisocyanate; mixing the resin composition with the polyisocyanate in the mixing chamber to form a mixture; and discharging the mixture from a dispensing gun to form the polyurethane foam.
18. 18. A method according to claim 17, characterized in that the physical blowing agent is selected from the group of cyclopentane, isopentane, n-pentane, trans-1,2-dichloroethylene, and mixtures thereof.
19. 19. A method according to claim 17, characterized in that the physical blowing agent is used in an amount of 10 to 40 parts by weight based on 100 parts by weight of the resin composition.
20. 20. - A method according to claim 17, characterized in that the resin composition has a hydroxyl content of at least 400 mg KOH / g.
21. 21. A method according to claim 17, characterized in that the Mannich polyol is used in an amount of from 20 to 40 parts by weight based on 100 parts by weight of the resin composition.
22. 22. A method according to claim 17, characterized in that at least one additional polyol is selected from the group of polyether polyols initiated with sucrose, polyether tetroles, polyether triols, and mixtures thereof.
23. 23. A method according to claim 17, characterized in that at least one additional polyol is used in an amount greater than 0 to 30 parts by weight based on 100 parts by weight of the resin composition.
24. 24. A method according to claim 17, characterized in that it comprises providing the resin composition in a stream from a supply vessel to the one spraying machine and from the spraying machine to the dispensing gun.
25. 25. A method according to claim 24, characterized in that the step of providing the resin composition is further defined as providing the resin composition separated from the isocyanate.
26. 26. A method according to claim 24, characterized in that it also comprises the step of monitoring levels of flammable gas to detect leaks in the current of the resin composition.
27. 27. A method according to claim 26, characterized in that it further comprises the step of deactivating the foam spray system in response to the detection of flammable gas levels above a predetermined threshold.
28. 28. A method according to claim 24, characterized in that it also comprises the step of storing the supply container for the resin composition in a storage room isolated from an area to be sprayed and isolated from an operating chamber that houses electric components.
29. 29. A method according to claim 28, characterized in that it also comprises the step of monitoring flammable gas levels within the storage room and deactivating the foam spray system in response to the detection of flammable gas levels above a predetermined threshold within the storage room.
30. 30. - A method according to claim 29, characterized in that it also comprises the step of venting the storage room to reduce the levels of flammable gas therein.
31. 31.- A method according to claim 30, characterized in that it also comprises the step of reactivating the foam spray system in response to the flammable gas levels that fall below the storage room.
32. 32. A method according to claim 28, characterized in that it also comprises the step of monitoring levels of flammable gas in the area to be sprayed and alerting the operator in response to the detection of flammable gas levels above a predetermined threshold in the area to be sprayed.